1) Field of the Invention
The present invention relates to faucets, and particular to a faucet for preventing cold water from flowing to the hot water tube, wherein the ratio of hot water and cold water is controllable.
2) Description of the Prior Art
Since hot water flow path is longer than that of cold water, pressure of cold water is larger than that of hot water. Thereby, cold water will flow to the hot water inlet so that the gas for warming the hot water will not burn completely. As a result, carbon monoxide will drain out or gas explosion occurs.
Referring to FIGS. 1A and 1B, a convention faucet is illustrated. The prior art faucet includes a water control body 1 with a rotatable control rod 11 at a center thereof, a water stop ring 2 at a lower end of the rotatable control rod 11 and rotatable synchronously with the rotatable control rod 11; a wire guiding ring 3 buckling an inner annular surface of the water control body 1; and a check structure below the wire guiding ring 3. The check structure has a water inlet thread sleeve 6. A positioning disk 7 with a confining groove 71 at a top thereof is installed within the sleeve 6. A weak spring 72 is installed in the confining groove 71. After the sleeve 6 is locked in the water control body 1, the weak spring 72 is compressed slightly so as to be formed with a buffer space. When the cool and hot water are mixed, the waterflow will compress the weak spring 72 in advance, and then the water flows into the outlet end from the water outlet 12 of the water control body 1, see FIG. 1A. When the pressure of cold water is larger than that of hot water, the pressure of cold water will push the positioning disk 7 to move downwards. By the resilient force of the weak spring 72, the lower end of the sleeve 6 is sealed to prevent the cold water from returning to the check structure. However, the structure of this prior art is complicated so that the cost in assembly is high. Furthermore, since the spring may fatigue, the lifetime will shorten. Thereby, after the faucet is used for a time period, it is possible that cold water can not be sealed effective.